The present invention relates to a RUGER® 10/22® semi-automatic .22 caliber rim fire rifle, and more particularly, to a conversion kit and method to convert the RUGER® rifle to shoot .17 caliber cartridges.
.22 caliber long rifle (22 LR) cartridges have been around for many decades and are used in target shooting, small game hunting and varmint hunting. The .22 LR cartridges have a rim fire ignition system versus a center fire system. The .22 LR bullet travels at approximately 1250 feet per second with a 1.9″ to 4.7″ drop from center at 100 yards. A common rifle action or receiver used for shooting the .22 LR's is the RUGER® 10/22® used in a semi-automatic .22 caliber rim fire carbine rifle.
Recently, a new cartridge has become popular. The .17 caliber Hornady Mach 2 (.17 HM 2) is a 17 grain polymer tipped bullet that is the same length of a .22 LR. However, the .17 HM 2 has significant advantages over the .22 LR in that it travels at approximately 2100 feet per second, or approximately twice the speed of sound, and has only a 0.5 inch center drop at 100 yards. Dedicated rifles with .17 caliber receivers and barrels are available to shoot the .17 caliber cartridges.
Because the .17 HM 2 cartridge is the same length, rim and maximum casing diameters as the .22 LR, rifle enthusiasts have tried to convert their RUGER® 10/22® semi-automatic .22 caliber rim fire rifle to shoot the .17 HM 2 by removing the .22 caliber barrel and retrofitting it with a .17 caliber barrel. However, because the .17 HM 2 has faster peak pressures than the .22 LR, dangerous premature extraction of the casing, case bulging and/or case rupturing have occurred, making this retrofit unsafe and hazardous to shoot.
There is a need for a conversion kit and method for converting the RUGER® 10/22® semi-automatic .22 caliber rim fire rifle to safely shoot .17 HM 2 or .17 caliber cartridges that are nearly twice as fast, more accurate and more destructive.